The Red Devils missed out on reaching the final for the first time in their history after suffering a 1-0 defeat against their neighbours in the closely contested semi-final.
Samuel Umtiti scored the only goal of the game early in the second half, beating Marouane Fellaini to the ball as he nodded in Antoine Griezmann’s 51st-minute corner.
Belgium – who had battled hard to beat Japan and Brazil in the previous knockout rounds – struggled to create chances despite dominating possession, managing just three shots on target over the 90 minutes.
“Were we as fresh as we were in the previous game? No. That’s only natural, it’s normal, but it’s not an excuse,” Martinez told the media.
“We had a team that we had to break the opposition down, that needs energy, sharpness. Maybe we suffered more than France, but I don’t think it’s a point you can raise in a World Cup.
“That’s part of being a champion. You need to be able to cope with travelling, with emotions of beating Brazil, with a big physical effort, with coping with a player who is suspended [in Thomas Meunier].
“We’re not going to look at it that way. What I take from the performance is that we never, ever got hurt on the counter-attack, which is what France wanted.
“Unfortunately, we lost because we conceded from a dead-ball situation. It happens in the box and you need to accept it.”
Belgium may not be in the final but they still have one game to play in Russia, as they will face the loser of Wednesday’s semi-final between Croatia and England in the third-place play-off.
Martinez praised his players for their efforts, not just against France but throughout the tournament, and challenged them to finish on a high.
“The disappointment is huge because the focus of the group was to try to win the tournament,” the former Everton manager added.
“It wasn’t about doing a good tournament or being happy in the top four. It is a really sad dressing room because the only focus that we had was being in the final. That makes me proud.
“We could have easily come to this stage and froze and not come to terms with what France have done in the past. France were in the final of the Euros and are almost used to being in these big games. I thought we coped with that side really well.
“I don’t want any of any players to be frustrated or disappointed. Now is the time to look forward to the final game.
“We wanted to be here to the end of the tournament, to play seven games, we’ve achieved that. We want to finish on a high. These players deserve to finish on a high.”